Researchers plan to launch a tiny spacecraft to Earth orbit and beyond within the next 18 months, in a key test of new propulsion technology that could help cut the cost of planetary exploration by a factor of 1,000.
The scientists and engineers are developing a new plasma propulsion system designed for ultrasmall CubeSats. If all goes well, they say, it may be possible to launch a life-detection mission to Jupiter's ocean-harboring moon Europa or other intriguing worlds for as little as $1 million in the not-too-distant future.
"We want to enable new missions that right now cost about $1 billion, or maybe $500 million — to go, for example, explore the moons of Jupiter and Saturn," said project leader Ben Longmier, a plasma physicist and assistant professor at the University of Michigan.
To get the ball rolling, Longmier and his team launched a crowdfunding campaign on the website Kickstarter Thursday (July 4). They hope to raise a minimum of $200,000 by Aug. 5, which should be enough to loft the miniature thruster on its maiden space voyage.
Miniature thruster technology
CubeSats are cheap and tiny spacecraft that weigh just 11 pounds (5 kilograms) or so. At present, they're generally restricted to Earth orbit, where they circle passively until their orbits decay and they die a fiery death in the planet's atmosphere.
But the new propulsion system — which the team calls the CubeSat Ambipolar Thruster, or CAT — could change all that, turning such bantam spacecraft into interplanetary probes, Longmier and his colleagues say.
CAT is a plasma engine, generating thrust by accelerating superheated ionized gas out of a discharge chamber. The CAT thruster is powered by solar panels, and permanent magnets will guide the plasma out the back of the spacecraft.
CAT is similar in concept to the ion engine that powers NASA's Dawn spacecraft, which orbited the protoplanet Vesta for more than a year and is now on its way to study Ceres, the largest body in the main asteroid belt between Mars and Jupiter. Over long periods of time, such thrusters can accelerate spacecraft to higher speeds than typical chemical rockets can achieve.
But with CAT, everything must work on the micro scale. The thruster and power systems will weigh less than 1 pound (0.5 kg), while the supply of propellant — likely either iodine or water, though many different substances could be used — will be capped at about 5.5 pounds (2.5 kg), researchers said.
Most of the CAT components have been built and tested individually, and the team is making good progress toward incorporating them into a unified whole, researchers said.
"The hurdles that exist right now are getting our newly designed thruster up and running. We think we're about three weeks from that," Longmier told SPACE.com. "We're really sort of ramping up and hitting full tilt right now."
To Earth orbit and beyond
The main goal of the new CAT Kickstarter campaign is to raise enough money to space-test the engine in Earth orbit. The team is planning to launch its first probe within the next 18 months, though it may be possible to get off the ground even sooner, Longmier said.
The team plans to send the maiden CAT-equipped probe out into deep space as well — not all the way to Europa or Saturn's geyser-spewing moon Enceladus, but far enough to demonstrate CAT's capabilities.